The present invention relates to undersea habitats for personnel and, more particularly, to such habitats that may be transported from site to site.
In the beginning, God created heaven and earth, and granted man xe2x80x9cdominion over the fish of the sea, the birds of the air, and over every living thing that moves upon the earthxe2x80x9d. Since then, with minimal success, man has endeavored to fulfill that mandate to have dominion over the sea. However, only in the past century has man progressed to achieve prolonged habitation in the waters which cover two thirds of our planet. It is most important to recognize that seventy percent of earth""s natural resources remain submerged. Perhaps the greatest challenge to continued underwater presence is the interface of air and sea where constant storms, icing, and tidal waves threaten all existence. Man is unequipped, when compared with aquatic mammals, to independently achieve a sustainable air supply in, or withstand the pressure of, ocean depths. Submarines including deep sea submersibles represent the most widely employed habitats presently available and provide limited ability for man to work at substantial depths. Only by providing a relatively stationary shelter within the sea, can there be sustained habitation so that personnel can work at substantial depths, and such a habitat must minimally provide ease of access, heat, sustenance, air replenishment, and communication with the surface. Three differing means of current art are now employed in effecting such a presence:
a. a structure affixed to the sea bottom
b. a cable lowered structure from a surface vessel
c. a mobile and submersible self-contained structure.
Each of these provides a measure of successful under sea presence, but each has limitations.
The fixed shelter is costly, is not easily repositioned, is difficult to maintain and repair, is dependent on its surface platform for power and sustenance, requires additional vessels to enlarge its area of search and survey, and has difficulties in transit from shelter to surface.
Although transportable, a cable lowered shelter lacks endurance because of the dependence on good weather, and it requires the same continuous supporting services. Its expense, the hazards of operation, and the need for portability limit both the habitat size and capability. This type of habitat is perhaps least able to provide safety and comfort.
The self-contained underwater vessel has advantages of mobility, independence from the surface, and lower operating costs. The submarine-type platform enables convenience of inspection, maintenance, and repair. However, as a habitat it has a limitation on ability to remain on site, suffers from a loss of communication, needs to resurface for replenishment of power and air supplies, and has restricted volume for stowage as needed for a sustained on-site presence.
Another habitat employs a ballast-induced rotation of a surface vessel into a vertical position. This is found to have an exaggerated motion in that position, as does a spar buoy, and there are difficulties with compartment reorientation from horizontal to vertical. Its ample stowage is also diminished by that shift of axis. The hydrodynamics of hull form are compromised by its design, and a return to port is required (and frequently dry-dock) for inspection, maintenance and repair. The acquisition costs, while less than for a bottom fixed shelter, are estimated to be greater than those for a self contained fixed shelter.
One significant purpose for all underwater habitats is the support and monitoring of divers entering into the water. While experimental diving has been successfully extended to 600 meters, the practical safe limits are but half of that. The transit of the diver from the surface is lengthy and hazardous, and the diver has a significantly limited bottom time which degrades with increasing depth. The time required to decompress also increases greatly as depth is increased, with a duration which may be measured in days.
Current efforts to harvest the sea""s resources by collecting marine samples and by performing archeological surveys in land salvage from the sea floor, have for reasons of lower cost and safety, resulted in the employment of unmanned remotely operated or autonomous vehicles. These vehicles, however, are regarded by some as inadequate, particularly when long term observation is required. Marine creatures are inclined to disperse from any intrusion upon their habitat. Tides and time of day can also vary both the presence and behavior of the aquatic life.
It is an object of the present invention to provide a novel movable undersea habitat which enables stays of long duration and which is readily movable from site to site.
It is also an object to provide such a mobile undersea habitat which includes an elongated support structure from the transport vessel and convenient means for access to and return from the habitat.
Another object is to provide such a mobile undersea habitat in which the habitat can be retrieved relatively quickly if required and the habitat is capable of self-contained operation for a reasonably extended period of time in the event of interruption of support systems from the transport vessel.
A further object is to provide such a mobile undersea habitat which can be fabricated relatively easily and economically from an existing vessel.
It has now been found that the foregoing and related objects can be readily attained by a mobile undersea habitat which includes an elongated vessel having a hull providing an elongated recess opening downwardly to the sea. A cooperatively dimensioned elongated column is seated within the recess and includes an elongated structural member and an elongated support member which extends in parallel spaced relationship to the structural member and means couple the support member to the structural member at spaced points along the length thereof. A conduit extends along the length of the structural member and is supported thereby. Support member pivot means pivotally mounts one end of the support member in the hull, and structural member pivot means pivotally mounts one end of the structural member in the hull at a point spaced from the support member pivot means. Also provided is means for raising and lowering the other end of the column.
An entrance is provided into the upper end of the conduit whereby persons and material may be moved therethrough, and a habitat is provided at the other end of the column and conduit. The habitat has a first passage to the conduit and a second passage to the exterior. The habitat is supported on a platform portion provided at the other end of the support member. Platform pivot means pivotally mounts the platform portion to the body of the support member, and habitat pivot means pivotally mounts the habitat to the other end of the conduit and structural member for movement about a pivot axis relative to the structural member. The platform and habitat pivot means together with the pivots to the hull cooperate to provide a horizontal orientation for the habitat at various angular orientations of the column.
The support member provides a hull closure panel for the opening in the hull when the column is pivoted upwardly into the opening. The support member is monolithic over its length to said platform portion. The structural member is a box-like girder extending about said conduit and there are also disposed in the girder cables and piping between the vessel and the habitat.
The coupling means comprises a multiplicity of supporting links spaced along the length of the structural member and support member, and link pivot means pivotally mount the ends of the links to the structural and support members. Desirably, hydraulic snubbers are provided adjacent the habitat between the support and structural members. The platform portion is a portion of the support member and the platform pivot means is provided therebetween.
A transport capsule is movable within the conduit for transportation of persons and material, and there is included means for moving the capsule between the vessel and the habitat. The habitat pivot means includes cooperating and interfitting generally cylindrical elements on the conduit and the habitat.
At least one ballast chamber is provided on the column adjacent the habitat to control the buoyancy of the assembly of the column, conduit and habitat and thereby the angular orientation of the assembly relative to the vessel. Also included is means to admit water to the ballast chamber and means to expel water from the ballast chamber to achieve the desired buoyancy.
Preferably, the habitat includes a diving bell access hatch. Cables are connected between the hull and the support member adjacent the habitat to provide means for retracting the column, into the hull opening and winches pay out and retrieve the cables. A multiplicity of cables and tubes or pipes extend from the vessel to provide breathable gas, water, heat, communications and power to the habitat. Emergency air supply tanks are supported on the column adjacent the habitat for supply of breathable gas thereto.
Desirably, the habitat includes a cluster of interconnected spheroidal chambers. A gallery is provided about the upper end of the habitat and the lower end of the conduit for access to the conduit from a plurality of the spheroidal elements.
The spacing between the pivots at the upper end of the structural and support members is substantially the same as the spacing between the pivots at the lower ends of the spherical and support members, whereby the ends of the structural and support members define a parallelogram to orient the platform portion and habitat in a horizontal attitude.
Generally, the pivot axis of the structural member is spaced horizontally and upwardly from that of the support member.